1
Squirrel's Pick Squirrel's PickThe best game on this page. If you only try one, try this.
Base-BuildingSpaceColony Sim
$24.99 ~47.1 hr median no co-op complexity: moderate 85.8% of 11k
The Squirrel's verdictSpace Haven centers on colony management at the crew level: building and maintaining vessels room by room, tracking individual crew needs, and balancing resources across interacting ship systems. That puts it far closer to Rimworld-in-space than to X4's galaxy-scale trading and fleet combat. Reviewers describe the tutorial as demanding and the UI as friction-heavy compared to similar colony builders.
Not for you if you want galaxy-scale trading and fleet combat rather than managing individual crew members and ship systems in close detail.
2
Closest Match Closest MatchThe most similar game to the anchor, by what players say.
SpaceSci-fiSpace Sim
$15.99 ~83 hr median no co-op complexity: heavy 85.4% of 3k
The Squirrel's verdictX3: Terran Conflict covers the same ground as X4 — sector economy, fleet automation, trade empires built from nothing — but reviewers describe a clearer sense of progression once the opening grind unlocks. Median playtime sits at 83 hours, and players who push past the steep early curve consistently describe one of the deepest single-player space sims available. The target is players who prioritize systemic depth over visual polish or accessibility.
Not for you if you want modern visuals, capital-ship spectacle, or aren't prepared to grind through a punishing early phase before the game opens up.
3
Sci-fiTactical RPGTrading
Strong Mods Strong ModsA deep, active modding scene extends it past its base content.
$14.99 ~70.9 hr median no co-op complexity: heavy 83.6% of 4k
The Squirrel's verdictSame open-ended space sandbox with overlapping economy, combat, and faction systems to master, but Star Traders trades 3D ship simulation for text-and-menu crew management and turn-based encounters. It's built around RNG-driven skill checks and permadeath runs rather than X4's persistent single-galaxy build-up, so progress resets instead of accumulating.
Not for you if you want direct ship-flying and visual capital-ship combat instead of menu-driven crew checks and heavy random dice rolls.
4
Space SimSpaceExploration
$24.99 ~19.4 hr median co-op complexity: heavy 83.3% of 444
The Squirrel's verdictBoth put you in an open sandbox of trading, mining, and combat across a persistent universe, with ships you build and modify yourself. Evochron Legacy trades X4's capital-ship scale for tighter, physics-driven single-seat flight and a much faster loop into money-making activities, with median playtime around 19 hours rather than hundreds.
Not for you if you want X4's fleet command and capital ships rather than solo Newtonian dogfighting, or need deep narrative content instead of loosely connected trading and combat systems.
5
Budget Pick Budget PickThe best game here for the least money.
SpaceSci-fiEconomy
$4.99 ~29.5 hr median no co-op complexity: heavy 83% of 524
The Squirrel's verdictSame X-universe sandbox: trade, build factories, run fleets across gate-linked sectors, with the economy driving everything. X2 predates X4's scale and visual polish but has a single-player campaign with structured missions instead of an open-ended sim, giving newcomers a defined path through the learning curve rather than X4's tutorial-then-silence approach.
Not for you if you want X4's fleet scale and ship variety rather than an earlier, smaller entry with a guided campaign.
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Space SimOpen WorldAction
Strong Mods Strong ModsA deep, active modding scene extends it past its base content.
$9.99 ~42.6 hr median no co-op 80.2% of 672
The Squirrel's verdictNewtonian dogfighting combined with RTS-style fleet control is Void Destroyer 2's defining hook: you start in a single fighter and scale up gradually through a more directed campaign arc than X4's open-ended economy loop. Reviewers praise the dogfighting and ship variety at mid-scale, but also report frequent crashes and note that only a small fraction of owners finish the campaign.
Not for you if you need a stable, polished experience — reviews describe persistent crashes and significant drop-off before the campaign ends.
7
SpaceSci-fiSpace Sim
$14.99 ~23.2 hr median co-op 76.7% of 434
The Squirrel's verdictEvochron Mercenary keeps the open sandbox structure — trading, combat, and exploration across mapped and unmapped systems — but caps the scope at a single pilot and a hard five-slot upgrade limit per ship. There are fewer ship types than X4, no station-building, and no fleet management, but the on-ramp to actually flying and earning is shorter, with a median playtime of around 23 hours.
Not for you if you want X4's fleet command, capital ships, and station-building economy rather than a single heavily upgraded personal ship.
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SpaceSpace SimSci-fi
$9.99 ~14.2 hr median no co-op complexity: heavy 71.9% of 734
The Squirrel's verdictX3: Reunion shares X4's core loop — build trade empires, automate fleets, and script behavior across a persistent sector economy — but runs on jump-gate loading zones instead of a seamless universe and exposes an even rawer version of the same systems. Reviewers who stuck with it praise the scripting depth and economic complexity; the crashes and notoriously poor UI are real but don't define what veteran players come for.
Not for you if you found X4's onboarding inadequate — reviewers call this UI more confusing with no seamless travel.